Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
When you take a step, you are using up to 200 muscles.
886
Yawns are more contagious among people with closer relationships.
163
One human hair can support 3 ounces.
191
Enamel is hardest substance in the human body.
61
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The average person's skin weighs twice as much as their brain.
131
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73